An information processing device includes a motion information acquiring section that acquires a plurality of pieces of motion information showing a series of motions of a same kind performed by a plurality of users and a reference timing extracting section that extracts a reference timing based on a plurality of pieces of the motion information. Also included are an image information acquiring section that acquires a plurality of series of image information corresponding to a plurality of pieces of the motion information and a synchronization processing section that synchronizes a plurality of pieces of the image information based on the reference timing.